Devices for operatively displacing articles being transported along a moving article-transporting path, such as a conveyor belt or the like, into or onto an adjacent or associated discharge path or conveyor or slide or other receiving surface are known in the art. Such a device is, for example, disclosed in Federal Republic of Germany Utility Model 77 10 777.
Another such discharge device is shown in Federal Republic of Germany 31 41 100 A1, in which one arm of a three-armed spider is rotated into the transport conveyor path. The arm thereby contacts the front edge of an advancing article or parcel to be discharged whereby the article is partially rotated for displacement onto the associated discharge conveyor or surface. This device requires that there be suitable spacing between individual articles being transported on the transport conveyor. Moreover, if the parcel is not grasped or deflected by the rotating arm at its front corner, as will often occur where an article has an arcuately-shaped or rounded end, the article will not be rotated by the arm and, for parallel displacement arrangements, the article may strike directly against and be halted by a guide roller of the device.
Another known article displacement device, disclosed in Federal Republic of Germany 36 24 411 A1, includes a four-arm spider. Since one arm always extends into the conveyance path, the spider is disposed above the articles and carries, on its arms, downwardly swingable push-off plates for contact with the conveyed articles. The push-off plates turn relative to the arms with rotation of the spider. When an article to be displaced is not grasped at its center of gravity or center of frictional resistance, the article may cant in an uncontrolled manner and, in addition, may carry with it onto the discharge path the next-following article advancing along the conveyance path. Furthermore, in this known device the push-off plates are fully rotatable and slide along the articles that they are to displace. Due to the arcuate course that an article follows in its displacement from the conveyance path, however, there is undesirable relative movement between the article and the push-off plate.